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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        const array=[1,2,5,6,8,4,1,2,3];
        // array.forEach(function(currentValue,index,arr) {
        //     console.log(currentValue);  //array里的值,当前元素
        //     console.log(index);   //下标索引值
        //     console.log(arr);    //原数组
        // });

        array.forEach(function(value,index,arr) {
            console.log(value); //
            console.log(index); //
            console.log(arr); //
        })
        // console.log(array.__proto__===Array.prototype);
    </script>
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